Aim To investigate the effects of predni-sone on trabecular microstructure and biomechanical properties of femur in a rat model of type II collagen-induced arthritis (CIA ) using micro-CT and biome-chanics.Methods Forty 8-week-old male Lewis rats were randomly divided into 2 groups:control (CON ) group with 6 rats,and the remaining 34 rats were used to establish the CIA model.3 weeks after immunization screening CIA rats were randomly divided into CIA group,CIA plus prednisone 4.5 mg · kg-1 · d -1 group and CIA plus prednisone 9 mg · kg-1 · d -1 group.Rats in CON group were given vehicle as well as in CIA group.Rats in the other two groups were treated with prednisone at 4.5 mg·kg-1 ·d -1 or 9 mg ·kg-1 · d -1 .After 90 days treatment,all rats were euthanized,and the left femur was collected for biome-chanics,micro-CT scanning and three-dimensional re-construction.Results Micro-CT data showed that tra-becular thickness,trabecular number,bone volume/total volume,bone mineral density in CIA group were significantly lower than those in CON group.While tra-becular separation,structure model index were signifi-cantly higher than those in CON group.Compared with CON group,biomechanical properties (elastic load, maximum load,break load and stiffness)were signifi-cantly decreased in CIA group.Compared with CIA group,bone volume/total volume and trabecular num-ber were increased,while trabecular separation was significantly decreased in two prednisone groups.Com-pared with CIA group,there was no significant change in biomechanical properties in two prednisone groups. Conclusions Treatment with prednisone for 3 months can ameliorate the damage of trabecular microstructure of the femur in CIA rats,but it has no effect on biome-chanical properties and bone mineral density.

Objective: To explore the differences in the gut microbiota of primary school students with different levels of sugar sweetened beverage intake, so as to provide scientific evidence for better identification of health risks in children and the development of targeted health policies. Methods: In June 2022, a total of 192 healthy primary school students from Chengdu were selected using a stratified cluster random sampling method. The sugar sweetened beverage intake was assessed through a dietary frequency questionnaire. Based on the median daily sugar sweetened beverage intake, primary school students were categorized into a low intake group ( n =96) and a high intake group ( n =96). The gut microbiota in fresh fecal samples from the two groups of primary school students was analyzed using 16S rRNA high throughput sequencing, and the diversity and community structure differences in the gut microbiota were compared. Results: Children in the low intake group had a sugar sweetened beverage intake of (21.3±1.6) mL/d, while the high intake group had an intake of (269.6±37.3) mL/d. Diversity analysis results showed that there were no statistically significant differences between the low intake and the high intake group in terms of α diversity metrics: Observed_otus index [298.50 (259.75, 342.25), 305.50 (244.25, 367.75)], Goods_coverage index [1.00 (1.00, 1.00), 1.00 (1.00, 1.00)], Chao index [304.18 (260.75, 348.78), 305.88 (245.68, 370.88)], Shannon index [5.88 (5.29, 6.45), 5.71 (4.89, 6.28)] and Simpson index [0.95 (0.91, 0.97), 0.94 (0.88, 0.97)] ( Z =-0.64, -0.76, -0.54, -1.76, -1.67, P >0.05). Furthermore, no statistically significant difference was observed in β diversity between the two groups ( R 2=0.006, P >0.05). At the genus level, the abundance of Blautia [0.033 (0.018, 0.055)] and Fusicatenibacter [0.009 (0.005, 0.015)] were higher in the low intake group compared to the high intake group [0.024 (0.013, 0.041),0.006 (0.003, 0.011)]and differences were statistically significant ( Z =-2.52, -2.81, P <0.05). LEfSe analysis highlighted intergroup differences primarily in Blautia, Fusicatenibacter and Sarcina( LDA= 3.56,3.12,3.53, P <0.05). Conclusions There is no significant difference in the diversity and overall structure of the gut microbiota in primary school students with different levels of sugar sweetened beverage intake. However, there are species variations at the genus level. The information can serve as a scientific basis for identifying health risks in primary school students and formulating targeted health strategies.

Objective To analyze the scores of National Institutes of Health stroke scale(NIHSS),geriatric nutritional risk index(GNRI),motor function in dependence measure(MFIM)and the risk of stroke-related pneumonia(SAP).Methods Patients with stroke admitted from November,2021 to May,2022 were included.The scores of NIHSS,GNRI and MFIM at admission were collected,and they were divided into non-SAP group(n=232)and SAP group(n=86)according to whether pneumonia occurred within one week after stroke.According to the receiver operating characteristic(ROC)curve,the predictive ability of each score to SAP was evaluated,and each score was grouped according to the best cut-off point.logistic regression model and restricted cubic spline were used to analyze the relationship between each score and SAP.Results A total of 318 stroke patients were enrolled in the study including 86 in SAP group and 232 in non-SAP group.Logistic regression shows that,levels of NIHSS score(OR=32.783,95％CI:16.366～65.671,P<0.001),MFIM score(OR=0.052,95％CI:0.027～0.100,P<0.001)and GNRI score(OR=0.262,95％CI:0.144～0.476,P<0.001)were associated with SAP.Restricted cubic spline analysis shows that,there was a nonlinear dose-response relationship between SAP risk and NIHSS score(P-general trend<0.001,P-nonlinear=0.002),GNRI score(P-general trend<0.001,P-nonlinear<0.001).Conclusion NIHSS,MFIM,and GNRI scores are associated with the risk of SAP in stroke patients,and some of them have nonlinear relationships.

In 2023，World Health Organization（WHO）announced that the pandemic of COVID-19 is over；while there was an epidemic of multi-pathogenic infections in the respiratory tract by the end of the year in China，indicating that high attention still need to be paid to infectious diseases. In the past one year，some breakthroughs for infectious diseases have been achieved.This article reviews the major events and research progress in the diagnosis，prevention and treatment of infectious diseases in 2023.

Scaffold-free tissue engineered cell sheet is an emerging technology in biomedical field. It can avoid the adverse effects of scaffold materials, and can be further assembled to form more complex three-dimensional functional tissues. The construction of cell sheet is mainly based on the culture substrate composed of sensitive materials. By changing the stimulation factors such as temperature, enzyme, light, ion, redox, pH and sugar, the adhesion behavior of the substrate to the cells could be changed to make the cells detach naturally, thus generating the cell sheet. Recent years have seen the development of various simple and efficient construction technologies of cell sheet due to the development of a variety of novel sensitive culture substrates. The resulted cell sheets with excellent performance have greatly expanded their applications. This review summarized the construction methods of tissue engineered cell sheet and discussed the challenges and future perspectives in this field.
Temperature ; Tissue Engineering ; Tissue Scaffolds